1. Field of the Invention
This invention relates broadly to endoscopic instruments. More particularly, this invention relates to multiple sample endoscopic urological biopsy forceps.
2. State of the Art
Endoscopic biopsy procedures are typically performed with an endoscope and an endoscopic biopsy forceps device (bioptome). Some endoscopes are rigid and relatively short and are used in conjunction with cannulas or trocar tubes. Other endoscopes have a long flexible tube carrying fiber optics and typically having a narrow lumen through which the bioptome is inserted. Which endoscope is used will depend on the location of the biopsy site. The bioptome typically includes a long flexible coil (or a relatively short rigid tube depending on Which type of endoscope or cannula is used) having a pair of opposed jaws at the distal end and manual actuation means at the proximal end. Manipulation of the actuation means opens and closes the jaws. During a biopsy tissue sampling operation, the practitioner guides the endoscope to the biopsy site while viewing the biopsy site through the fiber optics of the endoscope. The bioptome is inserted through the narrow lumen of the endoscope or through a lumen of another device such as a trocar, catheter or needle, until the opposed jaws arrive at the biopsy site. While viewing the biopsy site through the fiber optics of the endoscope, the practitioner positions the jaws around a tissue to be sampled and manipulates the actuation means so that the jaws close around the tissue. A sample of the tissue is then cut and/or torn away from the biopsy site while it is trapped between the jaws of the bioptome. Keeping the jaws closed, the practitioner withdraws the bioptome from the lumen. The biopsy tissue sample must then be removed from the jaws.
When specifically used to gather tissue samples from the bladder of a patient, the above described procedure is known as a urological biopsy procedure. A urological biopsy procedure most often involves the taking of tissue samples from within the bladder of a patient suspected of having bladder cancer. In a cancerous bladder, evidence of the cancer may be found in the form of developing cancer cells in the muscle lining the walls of the bladder. When performing a urological biopsy procedure, the practitioner must usually take multiple biopsy samples. However, since the muscle in the bladder is covered with several layers of mucosal tissue, it is often difficult for the practitioner when using conventional endoscopic biopsy inset rudiments to find and gather tissue samples. In particular, the jaws of a conventional biopsy forceps are usually not sufficiently large to cut through the mucosal tissue and obtain a muscle biopsy. Another problem encountered by the practitioner performing a urological biopsy procedure is that the muscle tissue is very tough and requires a relatively strong shearing and/or cutting force. Since there is a limit as to how strong the tools of the art can be made and still be small and flexible enough for use in a urological biopsy procedure, there is always the possibility that the endoscopic forceps will break while in use. In such a case, the end effector or distal linkage may become lodged in the bladder and will require additional procedures to remove it.
As mentioned above, a proper urological biopsy procedure usually requires the taking of several tissue samples, as many as twelve, either from the same or different biopsy sites. Unfortunately, most endoscopic biopsy instruments are limited to taking a single tissue sample, after which the device must be withdrawn from the endoscope and the tissue collected before the device can be used again to take a second tissue sample. The single-sample limitation of these endoscopic biopsy instruments is due to the limited space between the biopsy forceps jaws.
Co-owned applications Ser. Nos. 08/355,057, filed Dec. 13, 1994 and 8/189,973, filed Feb. 1, 1994 disclose biopsy instruments where several tissue samples may be stored between the jaws of the jaw assembly when in the closed position. Although these multiple sample biopsy instruments represent an improvement over the prior art, the jaw configurations disclosed therein do not specifically address the problems associated with urgical biopsy procedures of locating and cutting the tough muscle tissue in the bladder.